What?​

Are you wanting to use PBS to backup your servers, but want to use TrueNAS as the storage handler?
I've been using this setup for the last few weeks and it has worked perfectly.

With the latest update of TrueNAS Community Edition, 25.04, you can run Linux Containers (LXC) natively on the system.

Why?​

This will allow you to have the ZFS back end of TrueNAS handle snapshots, replication, etc. for a robust storage layer. TrueNAS is a little more user friendly when it comes to managing the actual devices involved in the storage. You can easily expand the storage, divide it up for other uses, and run other services if you wanted to.

How?​

You will need TrueNAS 25.04 (or newer) in order to get LXC support.

️ Setting up the Debian container ️
We will be using a Debian LXC as the base for PBS.

Navigate to the Instance section within TrueNAS

And create a new instance with a Debian Bookworm image

(By default it will allow all RAM and CPU to be shared with the container, set this according to your needs)

Add a disk, create a new dataset for us with the PBS container
For the destination, I chose /mnt/pbs

If you'd like to use the same IP address as the TrueNAS system, add a proxy setting. I assigned the default ports used by PBS with HTTPS.

Press Create

(THIS PART COULD USE FEEDBACK FROM THE COMMUNITY, I'M NOT GOOD AT LINUX PERMISSIONS YET, THIS JUST WORKED FOR ME AND MAY NOT BE THE MOST SECURE SETTINGS)
Navigate to the dataset that was created and change the permissions to the preset ACL named "POSIX_OPEN" and set the owner and group to "backup"

Navigate back to the Instance page and connect to the container with the Shell button

️️ Installing PBS ️
Once you are in the shell of the container, set the root user password with
passwd

Create the directory that will be used for the PBS datastore (This will be the directory mounted in the LXC creation plus a folder inside of that)
mkdir /mnt/pbs/data

Run the following commands

# Update available repositories
apt update

# Install wget and nano
apt install wget nano

#Add the Proxmox repository key to the install
wget https://enterprise.proxmox.com/debian/proxmox-release-bookworm.gpg -O /etc/apt/trusted.gpg.d/proxmox-release-bookworm.gpg

Edit the apt repository list and add the Proxmox repositories
nano /etc/apt/sources.list

Add the following to the sources list

# PBS no-subscription
deb http://download.proxmox.com/debian/pbs bookworm pbs-no-subscription

# security updates
deb http://security.debian.org/debian-security bookworm-security main contrib

Update the apt repositories and install PBS

apt update
apt install proxmox-backup-server

Once the installation process if finished, should be able to connect to the TrueNAS IP but on port 8007 via HTTPS
Login using the root account and using the Linux PAM realm

Create a new datastore using the path that was created at the beginning of the PBS install

Press Add

The new dataset should be created and show the full size of the dataset that was created for the data in TrueNAS

This has been used heavily in my test environment and working perfectly as expected.

TrueNAS also has a scheduled snapshot created of the dataset every 6 hours and keep it for 3 days, hopefully to prevent accidental deletion or in an event where the PBS is subject to ransomware.

If you have any feedback, please leave it below and I will try to accommodate this guide as best as I can

I have since worked with the latest TrueNAS Scale. It's KVM. Seems flawless. I'm hopeful its as solid as it seems.

My scorn for the older revs remains. It's a poor tool for hosting. There are interface bugs that I've seen on multiple installations. The GUI becomes unware of the state of the VM. The virtual bridge can drop a NIC and insist that its up, or even do awful unknown ARP things that require a reboot of the host to resolve. These are all deal-breakers.

OP This is the worst possible way to setup PBS tbh, 1 hiccup on TrueNAS VM and you loose your storage and your backup/restore.
Best way according to my testing:
Separate VM's for PBS and TrueNAS with TrueNAS sharing an iscsi zvol directly to PBS, the block device is then formatted as an ext4 and mounted within PBS using fstab so it loads on startup.
Bam near 1:1 performance, with my testing I found that especially the garbage collection and verify tasks on iscsi take significantly less time then on NFS or SMB share

why not install the PBS directly on the TrueNAS system (without LXC or VMs)?

iXsystems positions SCALE as an appliance.

Basically Proxmox is doing the same with PVE. But Proxmox is "open"; the underlying Debian is unrestricted and you can do "everything" with it. Including strange things like installing Docker, for example. (No, please do not do that ;-) )

iXsystems enforces their known state of the system. Every single bit you change on the OS level by circumventing their middle-ware is problematic as the chance that this will be "undone" by SCALE is really high.

From my point of of view it is just impossible to install a complex software directly on SCALE. Note that installing PBS in parallel onto PVE is very well supported (while not recommended).

for your install command once the shell is loaded on the CT - a one liner to do all the steps you outlined @PwrBank

iXsystems enforces their known state of the system. Every single bit you change on the OS level by circumventing their middle-ware is problematic as the chance that this will be "undone" by SCALE is really high.

nothing in what the OP did does this

i thnk you are having a kneejerk anti-truenas situation, yes ix-systems opinonated lockdown can be infuriating, but it is utterly irrelevant to the thread at hand, there is no "installing complex software on to scale" there is using incus and LXC for the purpose for which it was designed, the container doesn't even run prvilieged.

pbs running in a incus LXC on truenas 25.04 is quite intriguing - i just moved my pbs from a synology DS1815+ using CIFS as a backend, to truenas using a ZFS dataset as a backend, the idea of using snapshots and exports should work reasonablly well as a last local resort (first will be a pbs replica i will setup on another NAS

and to really mess with you my truenas is virtualized on proxmox ;-)

you really just posted to piss on his parade, you know that right? we don't care you don't want this, good for you! gues what no one is going top make you do this, phew, huh.

nothing in what the OP did does this

Well, I was just answering to "install the PBS directly on the TrueNAS system (without LXC or VMs)" which implied for me "directly on the OS". Sorry if that impression was wrong.

you really just posted to piss on his parade

Ooops - not my intention.

TrueNAS is a fine product, and I've never stated otherwise. (( I had used it for years productive (at home), several years ago (pre Corral desaster) and I have a test-SCALE running... ))